The present invention relates to a direction reversal device for units which undergo back and forth movement, such as layering tables or similar changing units, particularly in textile machines, the device including at least one abutment rod which is movable with respect to a housing, and a resilient connection located between these abutting components and arranged to be effective in their longitudinal direction.
These various systems equipped with layering tables or other changing units which must undergo constant back and forth movement and in which the changes in direction of movement at the points of reversal desirably take place as abruptly as possible.
Consequently, high acceleration forces must be produced at the points of reversal.
Because of the sudden change in the direction of movement at the points of reversal, high stresses are imposed on the moving members and high output loads are placed on the associated drive units.
In order to keep the coats required for moving the layering tables within tenable limits, the components which are moved have been designed to be as lightweight as possible and, in addition, compromises had to be made regarding the reversal movement.
It has already been proposed to reduce the effect of the above-described drawbacks by the provision of resilient abutments at the points of reversal which take over part of the work required for reversing the direction of movement. These abutments have the drawback, however, that they can be optimally designed only for layering tables in certain speed ranges and the locations of the points of reversal change when there is a change in the speed of movement of the table.
When the speed of the table is increased, the locations of the points of reversal are displaced outwardly, i.e., the layering tables or changing devices execute a longer stroke.